I’m in the same boat. It’s one thing to have that option in place to ‘restrict’ a remote access playback, but it’s another thing to impose the same restriction on a local intranet.
Kind of sad that Plex devs have been ignoring their users on this issue since at least 2016 [in this post] and apparently are steadfast in their mindset (instead of what the users want).
Looks like I might be moving to Emby as well.